Advice on how to stay safe in hot weather has been issued as temperatures are set to rise over the next few days in Sussex.
Lots of sunshine and blue skies are expected in Sussex today, with temperatures of around 22 degrees, according to the Met Office.
Temperatures will rise to 25 on Friday and Saturday, before cooling down again on Sunday.
The Met office said that very warm air from Europe, which is in the middle of a heatwave, was being drawn to the UK.
The Health Heat Watch service has been set at level 2 for the south east due to the hot weather - which means that social and healthcare services should be 'ready and alert'.
The South East Coast Ambulance Service has said it is expecting a rise in demand for its services.
A spokesman tweeted: "With warmer weather having arrived and higher temperatures expected at the weekend please use us wisely.
"Hotter weather often leads to an increase in demand."
Calls relating to dehydration, heat stroke and sunburn typically increase, and higher temperatures can also seriously affect people with long-term health conditions such heart conditions or high blood pressure, the spokesman said.
Older people and the very young are also at higher risk of being affected.
SECAmb’s Executive Director of Operations, Joe Garcia said: “I’m sure many people are pleased to see the arrival of some warmer weather and we of course want people to enjoy the sun. However, we also need people to be sensible and use their common sense.
"This means covering up and using sun screen as well as drinking plenty of water.
“Everyone can benefit from this simple advice but there are some groups whose health can be particularly affected by the hotter weather including the very young, older people and anyone with certain long-term health conditions.
"If people know of anyone who could be especially vulnerable, then we’d ask them to check they’re ok.
“We’d also urge people to remember that we have a finite amount of resources to respond to patients.
"We are asking the public for their support in remembering that 999 should only be dialed in the event of a serious emergency.
"Health advice is also available by dialing NHS 111 or by speaking to a pharmacist."
For more advice on how to stay safe in hot weather, visit the ambulance service website here.
The Met Office has said that localised heatwaves are possible in a few places in the UK by Saturday.
The highest UK temperature ever recorded in June is 35.6 degrees, according to the Met Office.